51 lines
1.6 KiB
C++
51 lines
1.6 KiB
C++
// Copyright (c) 2023 Dominic Masters
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//
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// This software is released under the MIT License.
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// https://opensource.org/licenses/MIT
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#include "Ray3D.hpp"
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#include "assert/assert.hpp"
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using namespace Dawn;
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bool_t Dawn::raytestQuad(
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const struct Ray3D ray,
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const glm::vec2 min,
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const glm::vec2 max,
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const glm::mat4 transform,
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glm::vec3 &point,
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glm::vec3 &normal,
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float_t &distance
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) {
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// transform ray into local space of the quad
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glm::mat4 inverseTransform = glm::inverse(transform);
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glm::vec3 localRayOrigin = glm::vec3(
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inverseTransform * glm::vec4(ray.origin, 1.0f)
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);
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glm::vec3 localRayDirection = glm::vec3(
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inverseTransform * glm::vec4(ray.direction, 0.0f)
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);
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// perform ray-quad intersection test
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float_t t = -localRayOrigin.z / localRayDirection.z; // intersection distance along ray
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if(t < 0) return false; // intersection is behind the ray origin
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glm::vec2 intersectionPoint = (
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glm::vec2(localRayOrigin) + t * glm::vec2(localRayDirection)
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);
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if(
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glm::any(glm::lessThan(intersectionPoint, min)) ||
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glm::any(glm::greaterThan(intersectionPoint, max))
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) {
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return false; // intersection is outside the quad
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}
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distance = t;
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// compute point and normal of intersection in world space
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glm::vec3 localIntersectionPoint = glm::vec3(intersectionPoint, 0.0f);
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point = glm::vec3(transform * glm::vec4(localIntersectionPoint, 1.0f));
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normal = glm::normalize(
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glm::vec3(transform * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f))
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);
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return true; // intersection found
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} |